The present invention concerns computer system and pertains particularly to a device monitoring system with a dedicated bus and a dedicated processor.
Computer systems frequently include monitoring devices for sensing anomalous states of the system and system components. Temperature/voltage probes, sense switches to monitor whether the chassis door is open or closed, relays to control power to the system, are examples of such monitoring devices which sense anomalous states of the system and system components.
Monitoring devices have typically been attached to the computing system in an ad hoc manner. Typically, a monitoring device is mapped to some location in memory of the computing system or mapped via I/O registers. The difficulty this creates is that every computing system needs a unique piece of software to communicate with each of the monitoring devices. This unnecessarily proliferates the number of unique pieces of software that need to be written for managing/monitoring the computing system, thus increasing cost for the system vendor.
Some vendors have attempted to solve this problem by using a standard I.sup.2 C bus to attach to all of the monitoring devices. The I.sup.2 C bus is a hardware bus developed by Philips Semiconductors, having a business address of 811 East Arques Avenue, Sunnyvale, Calif. 94086-4523. The I.sup.2 C bus allows a simplified scheme for the attachment of monitoring busses within a computing system; however, use of an I.sup.2 C bus leaves a host of other problems not addressed.
For example, monitoring devices connected to a I.sup.2 C bus need to be polled by the central processing unit (CPU) of the computing system. This increases the load on the CPU and decreases the performance of the computing system.
Additionally, I.sup.2 C addresses for each monitoring device connected to an I.sup.2 C must be pre-configured or hard-wired. This reduces flexibility and limits the number of monitoring devices that can be monitored due to a limited number of I.sup.2 C addresses (127) available.
Also, monitoring devices need to be individually monitored by the computing system. Thus, as the number of monitoring devices increases so does the number of pieces of monitor device specific monitoring software necessary to be running on the computing system. The specific software pieces often need to be written for multiple operating systems thereby further exacerbating the software writing task.